Breathable absorbent articles having odor control

ABSTRACT

The present invention relates to absorbent articles in particular sanitary napkins with improved comfort, particularly by the incorporation of breathable backsheets while maintaining protection level performance and having an improved odour control performance. This has been achieved by the selection of individual elements for the absorbent article including an odour control system which meet specified requirements, which are then joined such that the absorbent article meets specific criteria in terms of comfort and protection and provides improved odour control performance.

FIELD OF THE INVENTION

The present invention relates to absorbent articles in particularsanitary napkins and panty liners which are breathable and have animproved odour control system.

BACKGROUND OF THE INVENTION

The primary consumer needs which underlie development in the absorbentarticle field, in particular catamenials is the provision of productsproviding both a high protection and comfort level.

One means for providing consumer comfort benefits in absorbent articlesis by the provision of breathable products. Breathability has typicallyconcentrated on the incorporation of so called ‘breathable backsheets’in the absorbent articles. Commonly utilised breathable backsheets aremicroporous films and apertured formed films having directional fluidtransfer as disclosed in for example U.S. Pat. No. 4,591,523. Both thesetypes of breathable backsheets are vapour permeable allowing gaseousexchange with the environment. This thereby allows for the evaporationof a portion of the fluid stored in the core and increases thecirculation of air within the absorbent article. The latter isparticularly beneficial as it reduces the sticky feeling experienced bymany wearers during use, commonly associated with the presence of anapertured formed film or film like topsheet, particularly over extendedperiods of time. This is a result of topsheets designed to achieve aclean and dry appearance. These topsheets tend to be smooth therebyminimising the build up of fluid on the surface of the topsheet.However, these benefits are achieved at the expense of comfort,particularly under hot and humid conditions, when due to their smoothsurface texture they tend to become sticky to the skin.

However, the main drawback associated with the use of breathablebacksheets in absorbent articles is the negative effect on theprotection level performance, by leakage known as wet through onto theusers garment. Although, breathable backsheets in principle only allowthe transfer of materials in the gaseous state, physical mechanisms suchas extrusion, diffusion and capillary action may still occur and resultin the transfer of the fluids from the absorbent core through thebacksheet and onto the users garments. In particular, these mechanismsbecome more dominant if the product is utilised during physicalexertion, or for heavy discharge loads or over extended periods of time.Thus, whilst the incorporation of breathable backsheets in absorbentarticles is highly desirable from a comfort standpoint, since theprimary role of a backsheet still remains the prevention of liquidleakage, such breathable backsheets cannot be satisfactorilyincorporated into products.

The problem of wet through onto users garments due to the incorporationof such breathable backsheets in absorbent articles has indeed also beenrecognised in the art. Attempts to solve the problem have mainly residedin the use of multiple layer backsheets such as those illustrated inU.S. Pat. No. 4,341,216. Similarly European patent application no. 710471 discloses a breathable backsheet comprising an outer layer of a gaspermeable, hydrophobic, polymeric fibrous fabric and an inner layercomprising an apertured formed film having directional fluid transport.The backsheet construction preferably has no liquid transport/wetthrough under certain specified test conditions. Also European patentapplication no. 710 472 discloses a breathable backsheet consisting ofat least two breathable layers which are unattached to one another overthe core area. The backsheet construction preferably has no liquidtransport/wet through under certain specified test conditions.

U.S. Pat. No. 4,713,068 discloses a breathable clothlike barrier for useas an outer cover for absorbent articles. The barrier comprises at least2 layers, a first layer having a specified basis weight, fibre diameterand pore size and a second layer comprising a continuous film of poly(vinyl alcohol) having a specified thickness. The barrier also has aspecified water vapour transmission rate and level of impermeability.

However, none of the above proposed solutions have been able to providea fully satisfactory solution to the problem of breathable backsheet wetthrough under all conditions. Furthermore, another problem associatedwith the exemplified multi layer backsheets is an increase in totalthickness of the product and a reduction in the flexibility, both ofwhich result in a consumer noticeable reduction in product comfort.

An alternative proposed solution to the problem of breathable backsheetwet through relates to the improvement of the absorbent material suchthat little or no liquid comes into contact with the backsheet, therebypreventing wet through. This is typically achieved by increasing theamount of absorbent material in the article. However, this results in anabsorbent article which is extremely thick which is highly undesirablefrom a consumer comfort standpoint. Hence, the absorbent article whilsthaving the required protection level and still maintaining some comfortbenefits by the presence of the breathable backsheet, suffers from alack of comfort from a different source, in this case the increaseddimensions of the article.

In addition the above solution also results in a reduction in theflexibility of the article, particularly evident as an increase in thecross section stiffness. It is however also well established that inorder to be comfortable for the wearer absorbent articles need to becross sectionally flexible. It is believed that the more crosssectionally flexible an absorbent article is, the less will it benoticeable to the wearer. Thus flexibility is another highly desirablecomfort requirement of modern absorbent articles.

EPO 705 583 and EPO 705 584 propose longitudinally flexible absorbentarticles which are vapour permeable. However, the exemplified absorbentarticles are typically very thin and do not address the absorbencycapacity of the article or the problem of wet through.

Consequently, as the incorporation of breathable backsheets in absorbentarticles results in reduction of the protection level, further desirableproduct comfort modifications such as reducing the thickness of theproduct and improving the flexibility of the product which would furtheracerbate the problem may not be incorporated in the absorbent article.

Thus, there exists a dichotomy in the means available to provideincreased consumer comfort in absorbent products and acceptableprotection levels. It is therefore an objective of the present inventionto provide an absorbent article having improved comfort, by theprovision of breathability throughout the absorbent article and whichmaintains an acceptable level of protection.

It has now been found that this objective may be achieved by theprovision of an article whose individual elements must meet certain keyfunctional parameter criteria in terms of comfort provision and/orprotection such as the backsheet wet through/liquid permeability, thetopsheet dryness, the core caliper and core vapour or vapour/airpermeability. Furthermore, these elements are combined such that theresultant product, in addition to these individual elements, meetsoverall criteria such that it has a certain dryness index and sensoryindex. The present invention has identified the key components whichaffect the principle comfort requirements of flexibility, breathability,dryness and caliper and the key components of protection such as liquidretention/wet through and rewet. Surprisingly, it has been found thatthe specific combination of these components, provides an articledelivering both high protection levels as well as high comfort to theconsumer. In particular it is believed that breathability must beconsidered in terms of total article breathability in addition to thebacksheet breathability in order to provide a truly breathable product.

However, a new problem has now been identified which is related to theeffective incorporation of breathable backsheets in absorbent articlesso as to provide breathable absorbent articles. This problem concernsthe perceived increased ease of detection of malodourous compoundswithin the absorbent article by at least a proportion of users of thesebreathable products.

Malodourous compounds typically present in absorbent articles originatefrom a number of sources. Firstly, the components of the fluid dischargesuch as urine, perspiration, menstrual fluid and blood may themselvescontain odourous compounds. Secondly, malodourous compounds may begenerated as a result of the degradation of the components of the fluiddischarge. Thus there are a wide range of compounds which may be presentat some time during the use of an absorbent article which have anassociated malodour. These compounds include fatty acids, ammonia,amines, sulphur containing compounds and ketones and aldehydes andnumerous derivatives thereof.

It is believed that due to the very nature of a breathable absorbentproducts, malodourous compounds contained therein may, similar to airand vapour, be more readily exchanged with the environment. Hence, themalodourous compounds are able to escape from the article and aredissipated into the surroundings. Consequently, it is at least perceivedby a number of potential users of these products that malodourouscompounds are more easily detectable from breathable absorbent articlesthan from non breathable absorbent articles. The presence and detectionof malodourous compounds from absorbent articles is however highlyundesirable and may cause the wearer of these products extremeembarrassment and thus, the prevention of their detection is highlydesirable.

It is thus an objective of the present invention to provide an absorbentarticle which is breathable and provides the desired level of protectionand which reduces and preferably prevents the detection of odourouscompounds emanating therefrom in use.

It has now been found that the combination of breathable absorbentarticles with an odour control system provides not only the associatedbenefits of a truly breathable product as described herein above, butalso provides a more effective odour control system. In particular, ithas been surprisingly observed that the amount of odour control systemincorporated into such breathable articles may be reduced whilst stillmaintaining the same level of odour control as in a non breathableabsorbent article.

It is believed that the performance benefit of the odour control systemis due to an interaction of the breathable environment of the absorbentarticle and the odour control agent contained therein. This believed tobe due to a number of factors.

Firstly, the breathability of the article results in increased movementof the volatile malodourous compounds. Hence, the amount of actualphysical contact between these compounds and the odour control agentsincreases. Contact between the odour control agents and the malodourouscompounds is usually required in order to effective combat the odourouscompound. Frequently large quantities of odour control agent is requiredin absorbent article in order to be effective because the agents doesnot necessarily contact the malodourous compounds. In the presentinvention the effectiveness of the odour control agent is significantlyincreased and the full capacity of the odour control agents can beutilised.

Secondly, due to the breathability of the article, which reduces the hothumid and anaerobic environment between the skin of the wearer and thesurface of the absorbent article, the growth of microorganisms isreduced. Microorganisms are also known to be responsible for thegeneration of odourous compounds.

Thirdly, the reduction in the hot, humid and occlusive environmentbetween the vicinity of the skin of the wearer and the article itselfalso reduces the tendency of the wearer to perspire. Consequently, theamount of associated perspiration related odour will be reduced. Thus,the breathability of the article actually reduces the amount of odourgenerated within the absorbent article. As a result the odour controlsystem works more effectively on the remaining odourous compoundspresent in the article.

An additional benefit of the present invention is that the combinationof breathability and odour control leads to an improvement in theoverall dryness of the product. The breathability of the article allowsfor the evaporation of fluid from the article, and also as indicatedabove a reduction in the amount of perspiration generated by the wearerof the product and thus a reduction in hot and sweaty feelings oftenassociated with the presence of topsheets designed to retain a clean anddry surface. The article therefore needs to retain less fluid and can doso more effectively. Furthermore the odour control agents are alsotypically able to absorb fluid and thereby improve dryness.

SUMMARY OF THE INVENTION

The present invention relates to a breathable disposable absorbentarticle having an improved odour control comprising the followingelements:

a liquid pervious topsheet, an absorbent core and a breathablebacksheet, said absorbent core being positioned intermediate saidtopsheet and said backsheet, said topsheet, core and backsheet eachcomprising at least one layer. The topsheet has a liquid retention ofless than 0.22 g for a 2.0 g load in the topsheet liquid retention test.The core has a caliper of less than 12 mm and has a vapour permeabilityof at least 200 g/m²/24 hrs. as defined in the vapour permeability test.The breathable backsheet has a liquid permeability of less than 0.3 gfor a 7 ml. load as defined in the liquid permeability test. Theelements are joined such that said absorbent article has a dryness indexof greater than 0.5 and a sensory index of greater than 50. Furthermore,the disposable absorbent article also comprises an odour control systempreferably positioned within the absorbent core, which in combinationwith the specific construction of the absorbent article providesimproved odour control performance.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to absorbent disposable articles such assanitary napkins, panty liners, incontinence products and baby diapers.Typically such products comprise the elements of a liquid pervioustopsheet, a backsheet and an absorbent core intermediate said topsheetand said backsheet. According to the present invention the topsheet,backsheet and core may be selected from any of the known types of thesecomponents provided that they meet certain comfort and protectionperformance requirements detailed herein. In particular, the keyperformance criteria have been identified as; the topsheet liquidretention performance which gives an indication of the ability of thetopsheet to maintain a dry surface and thereby keep the skin of thewearer dry; the permeability of the absorbent core and its thicknesswhich relate to the absorbent capacity of the core and it ability toallow the flow of vapour and/or air through it and the backsheet wetthrough/liquid permeability which indicates the ability of thebreathable backsheet to retain the absorbed fluid. Furthermore, theindividual elements are joined, preferably utilising optimised joiningtechniques such that the final product also meets specific comfort andperformance level criteria also described herein. In addition theabsorbent article further comprises an odour control system which incombination with the specific absorbent article element selectionprovided an improved odour control performance.

Absorbent Article Components

The Topsheet

According to the present invention the absorbent article comprises as anessential component a topsheet. The topsheets suitable for use hereinmay be any topsheet known in the art.

The topsheets for use herein may comprise a single layer or amultiplicity of layers. In a preferred embodiment the topsheet comprisesa first layer which provides the user facing surface of the topsheet anda second layer between the first layer and the absorbent structure/core.The topsheet typically extends across the whole of the absorbentstructure and can extend into and form part of or all of the preferredsideflaps, side wrapping elements or wings.

The topsheet as a whole and hence each layer individually needs to becompliant, soft feeling, and non-irritating to the wearer's skin. Italso can have elastic characteristics allowing it to be stretched in oneor two directions. As used herein the topsheet hence refers to any layeror combination of layers whose principle function is the acquisition andtransport of fluid from the wearer towards the absorbent core.

According to the present invention the topsheet may be formed from anyof the materials available for this purpose and known in the art, suchas non wovens fabrics, films or combinations of both. In a preferredembodiment of the present invention at least one of the layers of thetopsheet comprises a liquid permeable apertured polymeric film.Preferably, the upper layer is provided by a film material havingapertures which are provided to facilitate liquid transport from thewearer facing surface towards the absorbent structure, as detailed forexample in U.S. Pat. Nos. 3,929,135, 4,151,240, 4,319,868, 4,324,426,4,343,314 and 4,591,523.

According to the present invention the topsheets suitable for use hereinmust have a topsheet liquid retention of less than 0.22 g, preferablyless than 0.15 g, more preferably less than 0.1 g, most preferably 0 g,as defined in the liquid retention test disclosed herein after.

Backsheet

The absorbent article according to the present invention also comprisesa breathable backsheet. The backsheet primarily prevents the extrudesabsorbed and contained in the absorbent structure from wetting articlesthat contact the absorbent product such as underpants, pants, pyjamasand undergarments thereby acting as a barrier to fluid transport. Inaddition however, the breathable backsheet of the present inventionpermits the transfer of at least vapour, preferably both vapour and airthrough it and thus allows the circulation of gases into and out of thebacksheet. The backsheet typically extends across the whole of theabsorbent structure and can extend into and form part of or allsideflaps, side wrapping elements or wings.

According to the present invention any known breathable backsheet ormultiple layer breathable backsheet composite may be used in theabsorbent article provided that the backsheet meets the requirement ofthe liquid permeability test as defined herein. The breathablebacksheets of the present invention have a liquid permeability at a 7 mlload of less than 0.3 g, preferably of less than 0.2 g, more preferablyless than 0.1 g most preferably 0 g.

According to the present invention suitable breathable backsheets foruse herein comprise at least one gas permeable layer. Suitable gaspermeable layers include 2 dimensional, planar micro and macro-porousfilms, macroscopically expanded films, formed apertured films andmonolithic films. According to the present invention the apertures insaid layer may be of any configuration, but are preferably spherical oroblong and may also be of varying dimensions. The apertures preferablyare evenly distributed across the entire surface of the layer, howeverlayers having only certain regions of the surface having apertures arealso envisioned.

Suitable 2 dimensional planar layers of the backsheet may be made of anymaterial known in the art, but are preferably manufactured from commonlyavailable polymeric materials. Suitable materials are for exampleGORE-TEX™ or Sympatex™ type materials well known in the art for theirapplication in so-called breathable clothing. Other suitable materialsinclude XMP-1001 of Minnesota Mining and Manufacturing Company, St.Paul, Minn., USA and Exxaire XBF-101W, supplied by the Exxon ChemicalCompany. As used herein the term 2 dimensional planar layer refers tolayers having a depth of less than 1 mm, preferably less than 0.5 mm,wherein the apertures have an average uniform diameter along theirlength and which do not protrude out of the plane of the layer. Theapertured materials for use as a backsheet in the present invention maybe produced using any of the methods known in the art such as describedin EPO 293 482 and the references therein. In addition the dimensions ofthe apertures produced by this method may be increased by applying aforce across the plane of the backsheet layer (i.e. stretching thelayer).

Suitable apertured formed films include films which have discreteapertures which extend beyond the horizontal plane of the garment facingsurface of the layer towards the core thereby forming protuberances. Theprotuberances have an orifice located at its terminating end. Preferablysaid protuberances are of a funnel shape, similar to those described inU.S. Pat. No. 3,929,135. The apertures located within the plane and theorifices located at the terminating end of protuberance themselves maybecircular or non circular provided the cross sectional dimension or areaof the orifice at the termination of the protuberance is smaller thanthe cross sectional dimension or area of the aperture located within thegarment facing surface of the layer. Preferably said apertured preformedfilms are uni directional such that they have at least substantially, ifnot complete one directional fluid transport towards the core.

Suitable macroscopically expanded films for use herein include films asdescribed in for example in U.S. Pat. Nos. 4,637,819 and 4,591,523.

Suitable monolithic films include Hytrel_, available from DuPontCorporation, USA, and other such materials as described in Index 93Congress, Session 7A “Adding value to Nonwovens”, J-C. Cardinal and Y.Trouilhet, DuPont de Nemours international S. A, Switzerland.

Preferred breathable backsheets for use herein are those having a highvapour exchange, most preferably both a high vapour and high airexchange.

Absorbent Core

According to the present invention the absorbent cores suitable for usein herein may be selected from any of the absorbent cores or core systemknown in the art provided that certain requirements as concerns caliperand vapour and/or air permeability as defined herein are meet. As usedherein the term absorbent core refers to any material or multiplematerial layers whose primary function is to absorb, store anddistribute fluid. The absorbent core of the present invention has avapour permeability of greater than 500 g/m²/s, preferably greater than800 g/m²/24 hrs., more preferably 1200 g/m²/24 hrs., most preferablygreater than 1500 g/m²/24 hrs. In a preferred embodiment of the presentinvention the absorbent core also has an air permeability of greaterthan 200 l/m²/s, more preferably greater than 800 l/m²/s, mostpreferably greater than 1200 l/m²/s. The absorbent core thus has acaliper of less than 12 mm, preferably less than 8 mm, more preferablyless than 5 mm, most preferably from 5 mm to 1.0 mm.

According to the present invention, the absorbent core can include thefollowing components: (a) an optional primary fluid distribution layerpreferably together with a secondary optional fluid distribution layer;(b) a fluid storage layer; (c) an optional fibrous (“dusting”) layerunderlying the storage layer; and (d) other optional components.

a Primary/Secondary Fluid Distribution Layer

One optional component of the absorbent core according to the presentinvention is a primary fluid distribution layer and a secondary fluiddistribution layer. The primary distribution layer typically underliesthe topsheet and is in fluid communication therewith. The topsheettransfers the acquired fluid to this primary distribution layer forultimate distribution to the storage layer. This transfer of fluidthrough the primary distribution layer occurs not only in the thickness,but also along the length and width directions of the absorbent product.The also optional but preferred secondary distribution layer typicallyunderlies the primary distribution layer and is in fluid communicationtherewith. The purpose of this secondary distribution layer is toreadily acquire fluid from the primary distribution layer and transferit rapidly to the underlying storage layer. This helps the fluidcapacity of the underlying storage layer to be fully utilised. The fluiddistribution layers can be comprised of any material typical for suchdistribution layers.

b Fluid Storage Layer

Positioned in fluid communication with, and typically underlying theprimary or secondary distribution layers, is a fluid storage layer. Thefluid storage layer can comprise any usual absorbent material orcombinations thereof. It preferably comprises absorbent gellingmaterials usually referred to as “hydrogel”, “superabsorbent”,hydrocolloid” materials in combination with suitable carriers.

The absorbent gelling materials are capable of absorbing largequantities of aqueous body fluids, and are further capable of retainingsuch absorbed fluids under moderate pressures. The absorbent gellingmaterials can be dispersed homogeneously or non-homogeneously in asuitable carrier. The suitable carriers, provided they are absorbent assuch, can also be used alone.

Suitable absorbent gelling materials for use herein will most oftencomprise a substantially water-insoluble, slightly cross-linked,partially neutralised, polymeric gelling material. This material forms ahydrogel upon contact with water Such polymer materials can be preparedfrom polymerizable, unsaturated, acid-containing monomers which are wellknown in the art.

Suitable carriers include materials which are conventionally utilised inabsorbent structures such as natural, modified or synthetic fibers,particularly modified or non-modified cellulose fibers, in the form offluff and/or tissues. Suitable carriers can be used together with theabsorbent gelling material, however, they can also be used alone or incombinations. Most preferred are tissue or tissue laminates in thecontext of sanitary napkins and panty liners.

An embodiment of the absorbent structure made according to the presentinvention comprises a double layer tissue laminate formed by folding thetissue onto itself. These layers can be joined to each other for exampleby adhesive or by mechanical interlocking or by hydrogen bridge bands.Absorbent gelling material or other optional material can be comprisedbetween the layers.

Modified cellulose fibers such as the stiffened cellulose fibers canalso be used. Synthetic fibers can also be used and include those madeof cellulose acetate, polyvinyl fluoride, polyvinylidene chloride,acrylics (such as Orion), polyvinyl acetate, non-soluble polyvinylalcohol, polyethylene, polypropylene, polyamides (such as nylon),polyesters, bicomponent fibers, tricomponent fibers, mixtures thereofand the like. Preferably, the fiber surfaces are hydrophilic or aretreated to be hydrophilic. The storage layer can also include fillermaterials, such as Perlite, diatomaceous earth, Vermiculite, etc., toimprove liquid retention.

If the absorbent gelling material is dispersed non-homogeneously in acarrier, the storage layer can nevertheless be locally homogenous, i.e.have a distribution gradient in one or several directions within thedimensions of the storage layer. Non-homogeneous distribution can alsorefer to laminates of carriers enclosing absorbent gelling materialspartially or fully.

c Optional Fibrous (“Dusting”) Layer

An optional component for inclusion in the absorbent core according tothe present invention is a fibrous layer adjacent to, and typicallyunderlying the storage layer. This underlying fibrous layer is typicallyreferred to as a “dusting” layer since it provides a substrate on whichto deposit absorbent gelling material in the storage layer duringmanufacture of the absorbent core. Indeed, in those instances where theabsorbent gelling material is in the form of macro structures such asfibers, sheets or strips, this fibrous “dusting” layer need not beincluded. However, this “dusting” layer provides some additionalfluid-handling capabilities such as rapid wicking of fluid along thelength of the pad.

d Other Optional Components of the Absorbent Structure

The absorbent core according to the present invention can include otheroptional components normally present in absorbent webs. For example, areinforcing scrim can be positioned within the respective layers, orbetween the respective layers, of the absorbent core. Such reinforcingscrims should be of such configuration as to not form interfacialbarriers to fluid transfer. Given the structural integrity that usuallyoccurs as a result of thermal bonding, reinforcing scrims are usuallynot required for thermally bonded absorbent structures.

Absorbent Article

The potential benefits of incorporating a breathable backsheet into anabsorbent structure have been extensively referred to in prior art but,a simple observation of available products in the market paces clearlypoints to a basic failure to realise a benefit in use. In many instancesthe problem has resulted from an inability to control through breathablebacksheet wet-through. According to the present invention the absorbentelements meeting the requirements as described herein above must as anessential requirement be combined such that the resultant absorbentarticle product meets certain performance and comfort indexes hereinreferred to as the sensory index and the dryness index. The drynessindex is a function of the effective breathability test and rewet testof the absorbent article and the sensory index is a function of theeffective breathability test, flexibility and caliper of the absorbentarticle. The test methods are defined herein after. The indices aredefined by the equations below:

Dryness index=Effective breathability/(Rewet test)

Sensory index=Effective breathability/(Flexibility*Caliper)

Dryness Index

The Dryness Index is a reflection of one of the unexpected interactionsthat an absorbent article, particularly a sanitary napkin needs tosatisfy, in order to provide overall dryness and/or comfort benefits tothe wearer of the product. The dryness index reflects that perceivedwetness in use is determined by both the dryness of the wearer facingsurface of the product that lies closest to the body in use (i.e.absorbent article rewet test) and the dryness that can be achieved viawater vapour exchange with the environment and air circulation via thebacksheet (i.e. effective breathability).

Effective Breathability

The effective breathability is determined from the equation below:

Effective Breathability=Vapour Permeability+0.25×Air Permeability

The effective breathability determines a numerical value for thebreathability. It considers the two key mechanisms that are likely toparticipate in exchange of humidity and temperature while wearing aabsorbent article having a breathable backsheet. The first mechanism iswater vapour exchange via the process of diffusion. This is a continuousprocess and the mechanism is well understood and represented by a simplediffusion equation. In addition, body motion can result in a change inthe relative position of the wearers body and the absorbent article, forexample between a sanitary article and the body known as gapping. Thismotion also is accompanied by a process of air exchange. Repetitivebodily motion can quite literally pump air into and out of the backsheetor at the sides of the product, where a product may not maintainintimate contact to the body. Naturally the stiffer an absorbent articleis in the genital region the less likely is this process of pumping todeliver an additional benefit to simple vapour exchange since theproduct is less deformable and is likely to press up closer to the bodylike a gasket.

The dryness index provides an indication of the ability of the articleto absorb fluids and thus provide protection to the consumer which isgiven as a function of the permeability of the article and the overallproduct dryness.

Sensory Index

The Sensory Index is an index that quantifies the relationship betweenproduct attributes that need to be satisfied in addition tobreathability to deliver a true benefit in use. This is due the crossinteractions between unexpected product design elements; namelybreathability, the product caliper and product stiffness/flexibility.

Thus in short, the sensory index values gives an indication of the rangeof values of the permeability, flexibility and caliper of the productaccording to the present invention which provides protection and comfortbenefits.

According to the present invention the absorbent article has a sensoryindex of greater than 50, preferably greater than 100, more preferablygreater than 200, most preferably greater than 300. The article furtherhas a dryness index of greater than 0.5, preferably greater than 2.0,more preferably greater than 4, most preferably greater than 10.

Odour Control System

According to the present invention the breathable absorbent articlescomprise as an essential feature an odour control system. It has beenfound that this combination of a breathable absorbent article with anodour control system results in an unexpected increase in theeffectiveness of the odour control system.

Any odour control agent or combinations thereof, known in the art forthis purpose may be used herein. The art is replete with descriptions ofvarious odour controlling agents for use in absorbent articles in orderto address the problem of malodour formation which may all be usefullyemployed in the present invention. These agents can typically beclassified according to the type of odour the agent is intended tocombat. Odours may be chemically classified as being acidic, basic orneutral. Acidic odour controlling agents have a pH greater than 7 andtypically include sodium carbonates, sodium bicarbonates, sodiumphosphates, particularly zinc and copper sulphates. Basic odourcontrolling agents have a pH of less than 7 and include compounds suchas carboxylic acids such as citric acid, laric acid, boric acid, adipicacid and maleic acid.

Neutral odour controlling agents have a pH of approximately 7. Examplesof these types of compounds include activated carbons, clays, zeolites,silicas, absorbent gelling materials, (AGM) and starches. Neutral odourcontrol agents and systems are disclosed for example in EPO 348 978, EPO510 619, WO 91/12029, WO 91/11977, WO 91/12030, WO 81/01643 andWO96/06589. Also cyclodextrin and derivatives thereof may be used asdescribed in U.S. Pat. No. 5,429,628.

Alternatively, the odour control systems may be categorised with respectto the mechanism by which the malodor detection is reduced or prevented.The above odour control agents typically control odour detection by anabsorptive mechanism.

Hence, odour control systems which chemically react with malodourouscompounds or with compounds which produce malodourous degradationproducts thereby generating compounds lacking odour or having an odouracceptable to consumers may also be utilised herein. Suitable agentsinclude chelating agents and may be selected from amino carboxylatessuch as for example ethylenediamine-tetracetate, as described forexample in U.S. Pat. No. 4,356,190, amino phosphonates such asethylenediaminetetrakis (methylene-phosphonates),polyfunctionally-substituted aromatic chelating agents as described inU.S. Pat. No. 3,812,044 and mixtures thereof. Without intending to bebound by theory it is believed that the benefit of these materials is inpart due to their exceptional ability to remove iron, copper, calcium,magnesium and manganese ions present in the absorbed fluids and theirdegradation products by the formation of chelates.

Another suitable odour control system for use herein comprises a buffersystem, such as citric acid and sodium bicarbonate, sodium phosphate andsorbic acid buffer systems. Also, buffer systems having a pH of from 7to 10 as described for example in WO94/25077 may be useful herein.

An alternative odour control system utilises ion exchange resins such asthose described in U.S. Pat. Nos. 4,289,513 and 3,340,875.

Masking agents such as perfumes may also be used as odour control agentsherein. Preferably these agents are used in combination with anadditional odour control agent such as zeolite as described inWO94/22500.

Preferred odour control systems for use herein include the followingcombinations i). silica, AGM and zeolites, preferably in a ratio of from5:1:1 to 1:1:5 most preferably 3:1:1 to 1:1:3 ii) zeolites, activatedcarbon and AGM, iii) silica and AGM preferably in a ratio of from 5:1 to1:5, more preferably from 3:1 to 1:3 iv) zeolites and AGM, v) silica andzeolites, preferably in a ratio of from 1:5 to 5:1, more preferably from1:3 to 3:1 vi). chelating agents, particularly ethylenediamine-tetracetate, and vii). chelating agents in combination with an odourcontrol absorber system i) or ii) preferably at a ratio of from 1:10 to10:1, more preferably from 1:5 to 5:1

According to the present invention the amount of odour control systemincorporated into the absorbent article may be readily determined by theman skilled in the art and is to some extend dependent on the end use ofthe absorbent article and bearing in mind the absorbent articledimensions. Typically the absorbent article comprises from 5 gm⁻² to 400gm⁻², more preferably from 100 gm⁻² to 300 gm⁻², most preferably from150 gm⁻² to 250 gm⁻² basis weight of said odour control system. Forexample a sanitary napkin or panty liner may comprise from 0.25 g to 5g, preferably from 0.4 g to 3 g, most preferably from 0.5 g to 2.5 g ofsaid odour control system.

The odour control system may be incorporated into the article by any ofthe methods disclosed in the art, provided that the absorbent articleelements and the absorbent article itself meets the specifiedrequirement described herein. For example, the odour control agents maybe layered on the core of the absorbent material or mixed within thefibres of the absorbent core. The odour control system is preferablyincorporated between two layers of cellulose tissue. Optionally theodour control system may be bonded between two cellulose tissue layerswith for example a hot melt adhesive or any suitable bonding system.

Absorbent Article Construction

A further aspect of the present invention relates to the joining of thetopsheet, backsheet and absorbent core elements to provide the absorbentarticle. According to the present invention at least two, preferably allof the elements of the article are joined.

Each of said elements comprising at least one layer has a wearer facingsurface and a garment facing surface. Typically, adjacent garment facingsurfaces form a common interface with the wearer facing surface of anadjacent element or layer. The elements or layers are joined togetheracross this common interface. In this manner the topsheet is joined tothe absorbent core, and the core is joined to the backsheet.Furthermore, each of said topsheet, backsheet and core elements maycomprise more than one layer and these layers may also be similarlyjoined. In addition the topsheet may be directly or indirectly by joinedto the backsheet at the periphery of the absorbent article.

The elements and layers thereof may be joined by any means known in theart for affixing two adjacent layers of material, such that the layersare directly attached to one another or directly attached to one anothervia the joining means. Suitable joining means include adhesive, fusionbonding, ultra sonic bonding, stitching, heat (e.g. crimping),embossing, and/or pressure bonds, or dynamic mechanical bonds. Accordingto an embodiment of the present invention the preferred means of joiningis adhesive. Suitable adhesives include non pressure sensitive and coldadhesives. The adhesive may be applied by any means known in the artsuch as spiral application, slot coating, spraying, spiral spraying,curtain coating, control coating and printing, provided that theadhesive does not substantially affect the breathability.

In a preferred embodiment of the present invention the inter element orinter layer joining adhesive is selected and applied so as to reduce anyimpact it may have on the effective breathability of the absorbentarticle and preferably also the flexibility of the absorbent article, Inthis manner the dryness index and sensory index values may in fact beincreased. Since many commonly utilised adhesives are not vapourpermeable it is highly preferable to minimise the amount of adhesiveused to join the layers/elements of the absorbent article in order tominimise their impact on the permeability (breathability) and preferablyalso the flexibility of the absorbent article. One means of achievingthis is to use particular adhesive application methods such as openadhesive application techniques, whereby areas of the common interfaceare adhesive free, whilst retaining the required level ofattachment/joining of the two adjacent layers or elements. In particularspiral spraying is preferred. The layers and elements should be joinedin such a manner so that the absorbent article product maintainsstructural integrity but no more. This method finds particularapplication for the interlayer joining of the backsheet element layersand the joining of the backsheet element and the absorbent core element.Alternatively adhesives which are vapour permeable may be used.

Preferably not more than 40%, more preferably less than 20%, mostpreferably less than 10% of the common interface of two adjacent layersor elements is joined. Furthermore, the density of the adhesive shouldbe reduced and a thin application of adhesive is preferred.

In a preferred embodiment of the present invention wherein the absorbentarticle finds utility as a sanitary napkin or panty liner, the absorbentarticle is also provided with a panty fastening means which providesmeans to attach the article to an undergarment. For example the pantyfastening means may comprise a mechanical fastener such as hook and loopfasteners such as marketed under the tradename VELCRO, snaps or holders.Alternatively, the article is fastened to the undergarment by means ofpanty fastening adhesive on the backsheet. The panty fastening adhesiveprovides a means for securing the article to the panty and preferably ameans for securing the article when soiled, to the fold and wrap packagefor convenient disposal. Typically, at least a portion of the garmentfacing surface of the backsheet is coated with adhesive to form thepanty fastening adhesive. Any adhesive or glue used in the art for suchpurposes can be used for the panty fastening adhesive herein. Pressuresensitive adhesives are most preferred. Suitable adhesives includeCentury A-305-IV manufactured by the Century Adhesives Corporation ofColumbus, Ohio, and Instant LOK 34-2823 manufactured by the NationalStarch and Chemical Company of Bridgewater, N.J., 3 Sigma 3153manufactured by 3 Sigma and Fuller H-2238ZP manufactured by the H.B.Fuller Co.

The panty fastening adhesive is typically applied to the backsheet byslot coating. In order to reduce the effect of the breathability of thebacksheet and thus of the article as a whole, the adhesive is preferablyapplied such that at least 60%, preferably from at least 80%, mostpreferably at least 90% of the surface of the backsheet is adhesivefree. The required adhesiveness can still be achieved even when usingreduced surface coverage by using a particular distribution such asthinner strips, discontinuous strips of adhesive, intermittent dots,random patterns spirals.

The panty fastening adhesive is typically covered with a removablerelease paper or film in order to prevent the adhesive from drying outor adhering to another surface other than the panty prior to use. Anycommercially available release paper or film may be used. Suitableexamples include BL 30MG-A SILOX EI/O and BL 30 MG-A SILOX 4 P/Oavailable from Akrosil Corporation.

According to the present invention the absorbent article can be usedbeneficially in the context of sanitary napkins, panty liners,incontinence articles and diapers. However, sanitary napkins and pantyliners are particularly susceptible to the present invention. Theabsorbent article may thus also have all those features and parts whichare typical for products in the context of their intended use such aselastic fastening devices and wings.

TEST METHODS Absorbent Article Component Tests

Topsheet Retention Test

The topsheet retention test is utilised to assess the liquid retentioncharacter (of bodily discharges) of topsheet materials or compositesthat may be used on disposable absorbent articles and particularlysanitary napkins.

Basic Principle of the Methods

The basic principal of the test is to evaluate the liquid retentionbehaviour of alternative topsheet materials to liquids that simulatebodily discharges. A “good topsheet material” in this test can be a film(e.g. apertured formed film) or a fibrous or a fibrous nature filmprovided it has a low propensity to acquiring and retaining liquidseither on or within its structure. Naturally a “good topsheet” is also,in addition to having low retention properties expected to allow rapidtransmission of bodily discharges further into the article and to hinderdischarges that are contained within the article from returning to theupper (body side) surface of the article. Additionally a “good topsheet”should also maintains a clean appearance during use of the articles.

To assess the topsheets retention to liquid, a test is performed asdetailed below:

Two sheets (with dimensions of 5 cm×5 cm) of a commercially availableairlayed absorbent tissue each with a basis weight of 63 g/m² availablefrom Walkisoft USA under the supplier code Metmar (P50W.IPED) areutilised to simulate an absorbent core.

A sample of the topsheet material (with dimensions of 5 cm×5 cm) that isto be assessed is placed directly on top of this absorbent structure. Astandardised test liquid closely matching menses in viscosity andelectrical conductivity (see below) is dripped onto the centre of thetest sample from a height of 3 cm and at a rate of 2 g/min. until atotal of 2 grams has been introduced onto the sample. The sample is leftwithout further interference for a period of 1 minute.

Following the 1 min. waiting period a transparent block (1 cm thick withdimensions 8.5 cm×8.5 cm) is placed on top of the test sample and aweight is lower gently onto the total assemble for a period of 5minutes. The total pressure exerted onto the test sample, at this point,is 70 g/cm².

The weight and transparent block is removed and carefully the topsheetsample is removed and placed on a stack of 2 sheets (with dimensions 12cm×12 cm) of commercially available filter/blotting paper {produced byCartiera Favini S.p.A. Italy; Type Abssorbente Bianca “N30” (localvendor Ditta Bragiola SpA. Perugia, Italy)} that have been pre-weighed.A second stack of 2 pre-weighed filter papers are placed on top of thetopsheet sample. A second weight is placed on top of the filter paperstack containing the topsheet sample. The second weight exerts apressure onto the filter paper stack of 130 g/cm² for a period of 15seconds. The weight (for this critical step) is attached to a hydraulicarm. The lowering of the weight and time the sample is placed underpressure is controlled via a simple electronic device to ensurereproduceability from one test to the next.

The second weight is removed and each (lying above and below thetopsheet sample) filter paper stack is weighed and the difference foreach surface (liquid pick-up from the topsheet sample) recorded.Materials that have a zero pick-up value for the top surface (placednormally in contact with the users skin) are given a zero “topsheetretention” value independent of having a non-zero value for the bottomsurface as these materials clearly demonstrate non-communication betweenthe upper and lower surfaces.

Test Solution: Preparation of Test Solution Paper Industry Fluid (PIF)

The test solution PIF is a widely used test liquid in the Paper industrydue to its simple composition, ability to prepare and maintain highstandards of solution quality and its similarity to human menses withrespect to viscosity and ionic surface tension.

The solution PIF is prepared by dissolving the following reagentcomponents, at the indicated quantities, into 1 liter of distilledwater. Care should be taken in dissolving the solid components andparticularly the Carboxylmethyl-cellulose. Typically the solidcomponents should be added over a period of one hour slowly and withconstant stirring of the solution (via a magnetic stirring device).

Supplier Sigma Chemicals, USA

Chemical Component - Usage/1L 1) Carboxymethylcellulose, Sodium salt lowviscosity: 15 grams Order No. = C 5678, 2) Sodium bi-Carbonate,Crystalline: Order No. = S 8875  4 grams 3) Sodium Chloride (AR): OrderNo. = S 9625 10 grams 4) Glycerol (>99% pure): Order No. = G 5516 80grams

REPRESENTATIVE TOPSHEET EXAMPLES

Representative topsheet samples commonly used in hygienic articles andavailable from a range of companies have been tested and the results aredetailed in the attached Table.

Material Sample Type Topsheet (supplier and material code) Retention (g)Example 1: CPM Top Surface = 0.00 Supplier Code: X-1522 Bottom Surface =0.09 Tredegar Film Products B.V. Holland Topsheet Retention = 0.00 *Example 2: Film/Nonwoven Composite** Film Supplier Code: BPC 5105 CPMTop Surface = 0.00 BP Chemical Germany Bottom Surface = 0.15 NonwovenSupplier Code: ARBO TB/_BI Topsheet Retention = 0.00 * Mequinenza SpainExample 3: CPT (LDPE) Top Surface = 0.00 Supplier Code: 15112 BottomSurface = 0.09 Tredegar Film Products B.V. Holland Topsheet Retention =0.00 * Example 4: Hydrophilic Thermally Bonded Nonwoven Top surface =0.10 Supplier Code: NW/ThBo/Hy Bottom Surface = 0.16 Pantex s.r.l(Italy) Topsheet Retention = 0.26 Example 5: Pantex Hydrophobic TopSurface = 0.09 Supplier Code: Pantex (PT2) Bottom Surface = 0.11 Pantexs.r.l (Italy) Topsheet Retention = 0.20 Example 6: Amoco Nonwoven TopSurface = 0.09 Supplier Code: Amoco P8 Bottom Surface = 0.09 Amoco GmbH,Germany Topsheet Retention = 0.18 **as found on current Alldays DuoActive panty liners manufactured by P & G Germany) *3-D apertured filmsdo not allow moisture on the bottom surface to migrate to the topsurface as evidenced by the top surface value hence zero is recorded forthe value of moisture in contact with the skin.

Vapour and Air Permeability Test: Absorbent Core

The air permeability test is utilised to assess the ability of theabsorbent core to exchange/circulate vapour and preferably air and iscarried out on the core material as detailed for an absorbent article.

Representative Absorbent Core Examples

The air/vapour permeability of representative examples of absorbent coreelements has been assessed. The absorbent core have been manufacturedunder normal manufacturing procedures by P & G Pescara Technical Centre(Italy) or removed from available market products.

Example 1

The core material is a tissue laminate (20 cm×6.5 cm) composed of afolded stack 2 layers of airlayed tissue of 63 g/m² basis weight{available from Walkisoft Finland under the supplier code Metmar(P50W.IPED)}. Between the two tissue layers the laminate contains AGM(available from Shokubai Japan under the supplier code; Aqualic L-74Optimised) at a basis weight of 50 g/m² and has a caliper of 2.2 mm.

Example 2

The core material is a tissue laminate (15 cm×4.0 cm) composed of a 2layers of airlayed tissue of 55 g/m² basis weight {available from UnikayItaly under the supplier code Unikay 303 LF}. Between the two tissuelayers the laminate contains AGM (available from DOW Chemicals Germanyunder the supplier code; DOW 95890.1) at a basis weight of 79 g/m², anda zeolite (available from Degussa Germany under the supplier code;Wessalith CS) at a basis weight of 105 g/m2. The core has a caliper of1.4 mm. The core laminate was manufactured and supplied by Korma Italy(under the manufacturing code: KO 040 02 003).

Example 3

The core material is a tissue laminate (20 cm×6.5 cm) composed of a 2layers of airlayed tissue of 55 g/m² basis weight {available from UnikayItaly under the supplier code Unikay 303 LF}. Between the two tissuelayers the laminate contains AGM (available from DOW Chemicals Germanyunder the supplier code; DOW 95890.1) at a basis weight of 67 g/m², azeolite (available from Degussa Germany under the supplier code;Wessalith CS) at a basis weight of 50 g/m² and activated charcoal(available from Chemviron Belgium under the supplier code; ChemvironSCII) at a basis weight of 40 g/m² The core has a caliper of 1.6 mm. Thecore laminate was manufactured and supplied by Korma Italy (under themanufacturing code: KO 065 01 003).

Vapour Air Caliper Permeability Permeability Examples mm g/m²/24 hrs.l/m²/s Example 1: 2.2 2034 4000 Example 2: 1.4 1990 2440 Example 3: 1.62010 2290

Liquid Permeability Test: Backsheet

The liquid permeability test is utilised to quantify the barrierproperties of breathable backsheet materials or constructions that couldbe utilised on a breathable absorbent article and particularly on asanitary napkin or a panty liner.

Basic Principle of the Methods

The basic principle of the test is to evaluate the performance ofbacksheet materials or constructions to liquids which simulate bodilydischarges. A “good backsheet layer or construction” is expected to besufficiently open to be classified as breathable but, without being tooopen to the passage of bodily discharges. To ensure that this test issufficiently representative to the situation when the absorbent articlein particular sanitary napkins is actually used a test solution closelyresembling human menses is utilised, referred to herein as ArtificialMenstrual Fluid (AMF). AMF is based on modified sheeps' blood asdetailed in the solution preparation method detailed below.

To determine the liquid permeability of a backsheet or backsheetconstruction, a standard absorbent structure with the backsheet materialor construction is prepared and placed flat on a transparent test standmade of transparent. The sample to be tested is oriented with theabsorbent structure exposed (upper side) and the breathable backsheetside in contact with the transparent test stand (lower side). Suspendedabove the sample to be analysed is a liquid delivery system that iscapable of delivering any desired quantity of the test liquid.

The standard absorbent structure is composed of 4 layers (folded as astack) of airlayed tissue of 63 g/m² basis weight {available fromWalkisoft USA under the supplier code Metmar (P50W.IPED)} havingdimensions of 20 cm×6.5 cm. The backsheet is then placed on top of thisstructure without any additional adhesive attachment.

Located between the back most surface (garment facing surface) of thetest sample and the transparent test stand are two sheets of absorbentfilter paper {produced by Cartiera Favini S.p.A. Italy; Type AbssorbenteBianca “N30” (local vendor Ditta Bragiola SpA. Perugia, Italy)}. Theabsorbent filter paper is in intimate contact with the backsheet of thetest sample to simulate, for example a sanitary napkin attached to apanty or a diaper/incontinence device in close contact with theclothing. Directly below the transparent test stand is a mirror sopositioned to allow any red colour change in the absorbent filter paperto be continuously observed. For example, if the backsheet is unable toadequately resist liquid transmission then the filter paper will becomewet with the red AMF solution and this can be observed in the mirror.The magnitude of the transmitted solution is determined by simplyweighing the absorbent filter paper.

The test solution is introduced to the test sample via a calibrateddelivery system such as via a simple burette according to the desiredtest approach as detailed below. Once loaded the test sample is thenplaced under a pressure of 70 g/cm² which is believed to reflect morestressful pressures that are nevertheless regularly obtained in-use. Thetest sample remains under the 70 g/m² pressure for a period of up to 5mins. At which time the weight is removed and the absorbent filter paperis weighted to determine if and to quantify the extent of liquid thathas been transported through the backsheet or backsheet construction.

The process is then repeated entirely with an additional introduction ofliquid to the test sample. For each introduction of liquid a new stackof absorbent filter papers (pre-weighed) is used to be able to betterdetermine the liquid barrier behaviour as a function of load.

The Loading Steps are Specifically:

Step 1 5 ml

Step 2 1 ml

Step 3 1 ml

A good backsheet layer or layered construction is expected to have aliquid permeability of less than 0.3 g for the above conditions.Preferred backsheet should also have a liquid permeability of less than0.3 g for step wise increased loads of 1 ml until a total load of 9 ml.,preferably 11 ml. more preferably 13 ml. and most preferably 15 ml. loadhas been reached.

Preparation of Test Liquid AMF

Artificial Menstrual Fluid (AMF) is based on modified sheep's blood thathas been modified to ensure it closely resembles human menstrual fluidin viscosity, electrical conductivity, surface tension and appearance.In addition we introduce a surfactant (1%) to this test fluid (suppliedby Pegesis/USA) to better reflect stress situations in which typicalhygiene practice (and in some limited situations, dietary influences)may introduce additional surfactants or unexpected levels of, forexample, fatty acids, that might lower the blood surface tension. Lowsurface tension menses is the biggest contributor to through backsheetwet-through failure on a breathable absorbent article such as a sanitaryarticle.

Reagents

1) Difibrinated sheep's blood is available from Unipath S.p.A{Garbagnate Milanese/Italy}.

2) Lactic Acid from J. T. Baker Holland Reagent Grade (85-95% w/w)

3) Potassium Hydroxide (KOH) from Sigma Chemical Co. USA, Reagent grade

4) Phosphate Buffer Saline Tablets from Sigma Chemical Co. USA, Reagentgrade

5) Sodium Chloride from Sigma Chemical Co. USA, Reagent grade

6) Gastric Mucine from Sigma Chemical Co. USA, Type III (CAS 84082-64-4)

7) Distilled Water.

Step 1

Prepare a 9±1% Lactic Acid Solution by dissolution of lactic acid powderand distilled water.

Step 2

Prepare a 10% Potassium Hydroxide (KOH) solution by dissolving KOHpowder into distilled water.

Step 3

Prepare a Phosphate buffer solution buffered to pH=7.2. by dissolvingtablets as directed into 1 L distilled water.

Step 4

Prepare and slowly heat to 45±5° C. a solution of the followingcomposition:

460±5 ml of phosphate buffer solution

7.5±0.5 ml of KOH solution

Step 5

Prepare a Mucous Solution by slowly dissolution (with constant stirring)of approximately 30 grams of gastric mucine in the pre-heated (45±5° C.)solution prepared in step 4. Once dissolved the solution temperatureshould be increased to between 50-80° C. and the mixture covered forapproximately 15 mins. Turn the heat down to maintain a relativelyconstant temperature between 40 and 50° C. and continue to stir for aperiod of 2.5 hrs.

Step 6

Remove the solution from the hot plate and allow the solution (from step5) to now cool to less than 40° C. Add 2.0 ml of the 10% lactic acidsolution and mix thoroughly for 2 mins.

Step 7

Place the solution in an Autoclave and heat to a temperature of 121° C.for 15 mins.

Step 8

Allow the solution to cool to room temperature and dilute 1 to 1 withthe di-fibrinated sheep's blood.

Following AMF preparation its viscosity, pH and conductivity aremeasured to ensure the blood characteristics lie in a range close tothat of normal menstrual blood {(see reference H. J. Bussing “zurBiochemie des Menstrualblutes” Zbl Gynaec, 179,456 (1957)}. Theviscosity should lie in the range of 7 to 8 (units cStK). The pH shouldlie in the range of 6.9 to 7.5 and the conductivity in the range 10.5 to13 (units mmho). If the viscosity is not within the range specifiedabove it should not be used and a new batch of AMF needs to be prepared.This may require adjustment to the quantity of gastric mucine used.Since this is a natural product its composition may alter from one lotto another.

For individual measurements typically 100 ml AMF test solution withsurfactant is prepared by mixing 90 ml AMF solution (maintained at 25°C.) with 10 ml Surfactant. The AMF/1% surfactant solution must beconstantly mixed to ensure the components do not separate prior tousage. The solution should be used only within 4 hours of preparation.

BACKSHEET EXAMPLES Example 1

In this example a backsheet currently incorporated in Always Ultra(normal size) available from Procter & Gamble Pescara Technical Centrewas tested. The backsheet supplied by Clopay USA (under supplier codeDH215 peach) is not a breathable backsheet.

Example 2

The backsheet is a multi-layer construction composed of two layers. Thefirst layer that is placed directly in contact with the absorbent tissuelayer is a formed apertured film (CPT) made of Low Density PE {suppliedby Tredegar Film Products B. V. Holland under the manufacturing codeX-1522}. The bottom most layer that would lie, in-use, directly incontact with the wearers panty is composed of a nonwoven laminate{14MB/14 SB manufactured by Corovin GmbH in Germany under the trade nameMD 2005}. The nonwoven laminate is composed of 14 g/m² spunbond and 14g/m² meltblown.

Example 3

The backsheet is comprised of two layers. The first layer is a formedapertured film made of a blend of low and high density PE with a crushresistant hexagonal hole configuration {supplied by Tredegar FilmProducts B.V. Holland under the manufacturing code AS 225 MD 25}. Thesecond layer is an improved nonwoven laminate composed of 3 layers withbasis weights 14 g/m² spunbond—20 g/m² meltblown—14 g/m² spunbond(manufactured by Corovin GmbH in Germany under the trade name MD 3005).

Example 4

This is also an example of a 2 layer backsheet construction. The firstlayer that is placed directly in contact with the absorbent tissue layeris a formed apertured film made of a blend of low and high density PEwith a crush resistant hexagonal hole configuration {supplied byTredegar Film Products B.V. Holland under the manufacturing code AS 225MD 25}. The second garment facing layer is composed of a simplemicroporous film {supplied by Exxon Chemical Company under themanufacturing code Exxaire XBF-102W}.

Example 5

In this example a single backsheet layer is utilised. The layer is alaminated nonwoven structure composed of a Polyethylene nonwoven(supplied by Corovin Germany under the code HDPE #17870) onto which auniform layer (0.8 mil/˜20 g/m²) of DuPont Hytrel (supplied by DuPontCorporation, USA) polyester-based film has been co-extruded. (thismaterial was manufactured at request of P & G Cin./USA by Clopay USAunder the trial code P18-3097/0.8).

Liquid Permeability (g) Example 7 ml 9 ml 11 ml 13 ml 15 ml Example 1zero zero zero zero zero Example 2 zero zero 0.2 0.4 0.55 Example 3 zerozero zero zero zero Example 4 zero zero zero zero ˜zero (commensing)Example 5 zero zero zero zero zero

ABSORBENT ARTICLE TESTS

The following tests were carried out on selected exemplified absorbentarticles detailed below:

REPRESENTATIVE EXAMPLES

Representative examples of sanitary napkins or panty liners according tothe present invention incorporating a breathable backsheet andmanufactured under normal manufacturing procedures by Procter & GamblePescara Technical Centre (Italy) SpA and Procter and Gamble GmbH Germanywere tested. An additional market product that does not feature abreathable backsheet has been included to provide a comparison ofproducts representative of current technology.

Example 1

In this example currently available Always Ultra (normal size) marketproduct was tested. The product was manufactured according to normalmanufacturing procedures by Procter & Gamble Pescara Technical Centre(Italy) SpA. The topsheet corresponds to the topsheet exemplified inexample 1 of the topsheet examples and the core corresponds to the coreexemplified in example 1 of the core examples. The backsheet on thisproduct is not a breathable backsheet.

Example 2

This is an example of a panty liner, which is based on currentlyavailable Alldays Duo Active, manufactured by Procter and Gamble inGermany. In this example the topsheet corresponds to the topsheetexemplified in example 2 of the topsheet examples and the corecorresponds to the core exemplified in example 2 of the core examples.However the backsheet consists of a multi-layer breathable backsheetconstruction as exemplified by example 2 in the backsheet retention testis used. The first backsheet layer that is placed directly in contactwith the absorbent core is a formed apertured film (CPT) made of LowDensity PE {supplied by Tredegar Film Products B.V. Holland under themanufacturing code X-1522}. The bottom most layer that would lie,in-use, directly in contact with the wearers panty (garment facinglayer) is composed of a nonwoven laminate {14MB/14SB manufactured byCorovin GmbH in Germany under the trade name MD 2005}. The nonwovenlaminate is composed of 14 g/m² spunbond and 14 g/m² meltblown. Eachbacksheet layer is joined over the full surface by a extensivelyoverlapped spiral glue application at a basis weight of approximately 8g/m². The glue utilised for attachment of both backsheet layers wassupplied by SAVARE' SpA. Italy (under the material code PM17). Theattachment of the product to the panty is provided for by five stripesof adhesive (material code Lunatak HL-2238 X supplied by Fuller GmbH,Germany). The stripes run the full panty liner length (about 150 mm) andeach is 5 mm wide.

Example 3

This example is a modified Always Ultra sanitary napkin. The topsheetcorresponds to the topsheet exemplified in example 1 of the topsheetexamples and the core corresponds to the core exemplified in example 3of the core examples. A multi-layer breathable backsheet construction asexemplified by example 3 in the backsheet retention test is used. Theformed apertured film backsheet layer utilised is a blend of low andhigh density PE with a crush resistant hexagonal hole configuration{supplied by Tredegar Film Products B.V. Holland under the manufacturingcode AS 225 HD 25}. The second backsheet layer is also an improvednonwoven laminate composed of 3 layers with basis weights 14 g/m²spunbond—20 g/m² meltblown—14 g/m² spunbond (manufactured by CorovinGmbH in Germany under the trade name MD 3005). In addition the interlayer/element glue attachment has been optimise to enhance both theflexibility and breathability of the article. The inter-layer gluingdesign is a low basis weight (6 g/m²) spiral glue pattern (2 spiralseach 10 mm wide and 160 mm long separated by 20 mm). This gluing designis used to join the first backsheet layer (apertured film) to theabsorbent core. The attachment of the second backsheet layer is via lowbasis weight spiral glue application only at the perimeter of theproduct. A glue free window of approximately 40 mm wide and 170 mm longand centered in the product is used to enhance the pad flexibility. Theglue utilised for joining of both backsheet layers was supplied bySAVARE' SpA. Italy (under the material code PM17). The attachment of theproduct to the panty is provided for by two stripes of adhesive(material code Lunatak HL-2238 X supplied by Fuller GmbH, Germany). Thestripes are 170 mm long, each is 22 mm wide and a gap of 11 mm existsbetween the stripes which are centered both length and breadthwise onthe article.

Example 4

This example is another example of a modified Always Ultra sanitarynapkin. The topsheet corresponds to the topsheet exemplified in example1 of the topsheet examples and the core corresponds to the coreexemplified in example 3 of the core examples. A two layer backsheetconstruction as exemplified by example 4 in the backsheet retention testis used. The first layer backsheet that is placed directly in contactwith the absorbent tissue core is a blend of low and high density PEwith a crush resistant hexagonal hole configuration {supplied byTredegar Film Products B.V. Holland under the manufacturing code AS 225HD 25}. The second backsheet layer that would lie, in-use, directly incontact with the wearers panty is composed of a microporous film{supplied by Exxon Chemical Company under the manufacturing code ExxaireXBF-102W}. The inter-layer/element gluing design is a low basis weight(6 g/m²) spiral glue pattern (2 spirals each 10 mm wide and 160 mm longseparated by 20 mm). This is used to join both the first backsheet layer(apertured film) to the absorbent core and the second microporous filmbacksheet layer to the first backsheet layer (the apertured film). Thesecond backsheet layer is also joined at the perimeter by atemperature/pressure fusion process (crimp) as utilised in the currentAlways market product in Europe. The glue utilised for joining bothbacksheet layers was supplied by SAVARE' SpA. Italy (under the materialcode PM17). The attachment of the product to the panty is identical tothat used in example 3.

Example 5

This example is again a sanitary napkin. The topsheet corresponds to thetopsheet exemplified in example 1 of the topsheet examples and the corecorresponds to the core exemplified in example 3 of the core examples.The backsheet utilised is exemplified by example 5 in the backsheetretention test and features a single layer laminated nonwoven structurecomposed of a Polyethylene nonwoven (supplied by Corovin Germany underthe code HDPE #17870) onto which a uniform layer (0.8 mil/˜20 g/m²) ofDuPont Hytrel (supplied by DuPont Corporation, USA) polyester-based filmhas been co-extruded. (this material was manufactured at request of P &G Cin./USA by Clopay USA under the trial code P18-3097/0.8). Thebacksheet is joined to the core using a low basis weight (6 g/m) spiralglue pattern ( 2 spirals each 10 mm wide and 160 mm long separated by 20mm). The attachment of the product to the panty is identical to thatused in example 3.

Example 6

In this example a market product has been assessed; The product,Silhouettes Ultra (normal plus size) Manufactured by Johnson & Johnson,Montreal Canada (Print code on bag; 51564 19:23) and imported into Italyby Johnson & Johnson Roma. The product claims an odor control benefit,but it does not contain a breathable backsheet and is thus notrepresentative of the present invention.

Air & Vapour Permeability Test on Absorbent Article Products

The Vapour permeability test is utilised to quantify the vapourtransmission properties of breathable absorbent articles.

Basic Principle of the Methods

The basic principle of the test is to quantify the extent of watervapour transmission of an absorbent article. The test method that isapplied is based on a standardized textile industry applied test methodand commonly referred to as the “cup test method”. The test is performedin a stable temperature/humidity laboratory maintained at a temperatureof 23° C. at 50% RH for a period of 24 hours.

Apparatus

1) Sample cup of dimensions specified in the drawing (open area=0.00059m²)

2) Syringe to introduce the distilled water into the completed samplecup.

3) Wax to seal the cup once sample has been arranged.

4) A circular punch to facilitate preparation circular samples ofdiameter=30 mm.

5) Laboratory of stable climatic conditions (23° C./±0.5° C.±50% RH±1%RH)

6) Laboratory balance accurate to 4 decimal places.

Sample Preparation/Measurements

The test is be performed on the absorbent article product. Arepresentative article is selected and a sample is cut to size using thepunch. The sample cut is sufficiently large to adequately overlap thesample holder and to ensure material that may have been damaged orundesirably stretched due to the cutting operation lies outside of themeasurement centre when the measurement is performed. The sample is soarranged onto of the sample cup so as to fully overlap the cup. Thesample is oriented so as to ensure that the surface exposed to thelaboratory environment is the same that would be found while wearing thearticle.

The closure ring of the sample cup is then placed onto the sample andpushed down. This ensures that the excess material is held firmly inplace and does not interfere with the measurement. A wax is then appliedto the entire surface of the closure ring to ensure the whole upper partof the apparatus is closed to the environment. Distilled water (5±0.25ml) is introduced with the syringe into the sealed sample cup via theminute perforation. Finally this perforation is sealed with siliconegrease.

The entire cup (containing sample and water) is weighed and the weightrecorded to 4 decimal places. The cup is then placed in a ventilationstream generated by a fan. The air flowing over the top of the samplecup is 3±0.3 m/sec and confirmed via a wind velocity meter (“Anemo”,supplied by Deuta SpA., Italy). The sample cup remains in the ventilatedtest field for a period of 24 hrs and is then re-weighted. During thisperiod if the test sample is sufficiently breathable the liquid in thesample holder is able to diffuse out of the sample holder and into thelaboratory environment. This results in a reduction in the weight ofwater in the sample holder that can be quantified on re-weighing thecomplete sample cup following the 24 hr period.

The vapour permeability value is determined as the weight loss dividedby the open area of the sample holder and quoted per day.

i.e. Vapour Permeability=Weight Loss (g)/(0.00059 m²/24 hrs)

Air Permeability Test

The air permeability test is utilised to assess the ability of anabsorbent structure to circulation/exchange air.

Basic Principle of the Methods

The basic principle of the test is to evaluate the resistance of anabsorbent article to the passage of air. In this test, the volume (oramount) of air that flows through an article of given dimensions understandard conditions (of 23° C./50% RH) is measured. The instrumentutilised for the test is: Air Permeabilimeter FX 3300 manufactured byTexTest AG Switzerland.

Samples should be allowed to equilibrate in the test environment for atleast 4 hrs prior to commencement of the measurement. The article(having dimensions exceeding 5 cm² the dimensions of the measurementhead) is placed on the device as instructed by the manufacturer. Anaspiration pump set to generate a pressure of 1210 kPa that sucks airthrough the sample layer or structure. The device measures the volume ofair flow and the pressure drop across the orifices that contains thesample and measurement head. Finally the device generates a value of airpermeability in the units of “I/m²/s”.

In the case of vapour and air permeability measurements on a finishedproduct the area of Panty Fastening Adhesive (PFA) can influence theresults particularly if the adhesive is applied as is typically the caseas an impervious stripe of adhesive via a slot coater. The measurementsof both air and vapour permeability need to be representative of thetotal product. One simple way to ensure a representative measurement isto assess backsheet samples with some PFA coverage. For example in thecase of Example 3, 4 and 5 the total backsheet area is covered to adegree of 45% with PFA. The vapour and air permeability measurements arethus performed on the samples featuring a 45% surface coverage by PFAadhesive.

Rewet Test

Basic Principle of the Methods

In this context the rewet method is utilised to assess the dryness ofthe product with respect to the wearer facing surface of the product .In combination with additional test methods that assess the dryness ofthe product with respect to the openness of the backsheet (air & vapourpermeability test) it allows the total product dryness to berepresented.

The test solution that is utilised for this test is based on the PaperIndustry Fluid (PIF) that has been extensively utilised (due to itsstability and high reproducibility) and due to its close similarity tohuman menses in terms of viscosity and liquid surface tension & ionicstrength. The solution preparation is detailed below.

Apparatus

1) Blotting Paper available from Schleicher & Schuell (Germany). S & SRundfilter/Durchmesser 150 mm, No. 597, Reference-No.: 311812.

2) A weight of 4200 g covered on the lower surface with a foam ofmoderate flexibility. Both the weight and foam are covered with a thin,flexible plastic film to maintain waterproofs. The weight dimensionsshould allow a 6 cm×10 cm surface to contact the article underexamination. Pressure exerted onto the article=70 g/cm².

3) A perspex (7 mm thick) plate of dimensions 6 cm×10 cm with a hole ofdimensions 3 cm×4 cm centred in the template.

4) A burette capable of introducing the test fluid at a reproduciblerate of 7 ml in 90 seconds.

5) An analytical balance capable of reading to 4 decimal places.

Sample Preparation/Measurement

The article to be assessed is removed from any packaging and placed on aflat laboratory surface and centred directly below the burette for testliquid delivery. The transparent plate is placed on the surface and thePIF test liquid is introduced over the exposed area corresponding to thehole in the transparent plate. After 90 seconds 3.5 ml of PIF have beenintroduced to the sample and an electronic counter set to 20 mins. isactivated. During this waiting period a stack of 7 discs of filter paperare weighed on the analytical balance and noted.

After 20 mins. the transparent plate is removed and the stack of filterpapers are positioned centrally on the article being assessed and theweight is gently lowered onto the filter paper stack. The article andfilter paper stack remain under the pressure exerted by the weight for aperiod of 15 seconds, after which the weight is carefully removed andthe filter paper stack is re-weighted. The difference in weight (to thenearest milligram) is recorded as the rewet value. The tests arerepeated for at least 10 samples to ensure adequate accuracy of themeasurements.

Flexibility Test & Caliper Test

Basic Principle of the Methods

The flexibility test is utilised to quantify the product flexibility orproduct stiffness in the cross direction. Most flexibility tests haveattempted to establish a product benefit based on a product designchange using a range of flexibility test methods to quantify this suchas measuring the drape (bend ability) of a product or the combination ofstiffness in both length and cross direction. The flexibility test usedherein is a dynamic stiffness measurement (force to deform vs. distancedeformed) which determines the resistance of a product to deform in thecross direction. The higher the stiffness value the more the product islikely to push against the sensitive skin of the wearers inner thighsand create a sensory negative during various bodily motions.

Apparatus

1) Climatically controlled Lab

Maintenance of 23° C. and 50% Relative humidity.

2) Instron Limited, UK Model 6021

Interfaced to a standard IBM with RS 232 interface for data logging.

Data are sent to the IBM computer in the form of distance and forcevalues.

Data is read into a standard Microsoft Excel worksheet for analysis.

Load cell=10 N

Initial clamp separation=55 mm

Final clamp separation=25 mm

Distance sample to be deformed=30 mm

Compression speed=25 mm /1 mins.

3) Caliper Measurement Device; Mitutoyo Instruments (Japan) Model543-601 B

The caliper is measured using a precision digital measurement device(±0.02 mm) with a circular measurement foot of 40 mm diameter thatexerts a pressure of 6.2 g/cm².

Sample Preparation

The tests are performed on the final form of the product identical inall ways and preferably on the same batch of products to be worn orassessed by a consumer.

In the case of a sanitary napkin, or light incontinence device theproduct is removed from packaging and any release paper that may be usedto maintain adhesives used to attached the article to a panty or otherpiece of clothing is be removed. Exposed glue surfaces (i.e. pantyfastening adhesive) are rendered inactive by lightly applying a talcumpowder to the adhesive surface.

Caliper Measurement

The Average caliper of the products is first determined. For productsthat are inherently flat the caliper at representative points (at least5) of the product is measured to determine an average value. Forproducts of complex shapes, such as relatively thick in the centre andrelatively thin in the extremities, a smaller measurement foot on thecaliper device (maintaining a measurement pressure of 6.2 g/cm²) is usedand to ensure at least 10 measurement points are utilised to moreaccurately determine the average product thickness.

Flexibility Measurement

The product is attached vertically between the clamps of the Instrondevice. The clamps are so positioned to start the compression (inproduct cross direction) from a distance of 55 mm. The sample iscompressed over a distance of 30 mm to a final clamp separation of 25mm. The instrument details are given above.

The Instron records the clamp separation (in mm) and the force exertedto achieve this separation and send this data via an RS232 interface toan IBM computer equipped with Microsoft windows 3.1 and Microsoft Excelversion 4.0. The force and distance data are loaded in to the Excelsoftware and the average force measurements over the full 30 mmcompression cycle is determined.

The measurements are performed on 10 samples of the same type to ensurea representative stiffness value to be determined for the sample underinvestigation.

The caliper of various core material are indicated under the coremeasurement table results. The results of caliper and flexibility testfor an number of absorbent article test products are given under thesensory index.

Sensory Index

The sensory index is a quantitative value that reflects how a productdesign impacts sensory perception. The sensory index is determined fromthe ration of;

Effective Breathability/Product Flexibility×Product Caliper

To determine the sensory index value the following 3 tests are to beperformed on the final product:

1) Effective Breathability Test.

2) Product Flexibility Test

3) Product Caliper Test

Effective Caliper Flexibility VP AP Breath- Sensory E.g (mm) (N)(g/m²/24 hr) (l/m²/s) ability Index 1 2.7 0.35 zero zero zero zero 2 2.20.8 690 545 826 469 3 3.0 0.39 780 775 973 779 4 2.8 0.41 635 zero 635553 5 2.7 0.34 580 zero 580 631 6 ˜3 1.5 zero zero zero zero VP = Vapourpermeability AP = Air permeability

VP=Vapour permeability

AP=Air permeability

Dryness Index

The dryness index is determined from the ratio of;

Effective Breathability/Product Wetness (Rewet)

To determine the dryness index value the following two tests are to beperformed on the final product:

1) Effective Breathability Test

2) Product Wetness (Rewet) test.

Permeability Permeability Rewet Vapour Air Effective Dryness E.g. (mg)(g/m²/24 hr.) (l/m²/sec) Breathability Index 1 50 zero zero zero zero 2200 690 545 826 4.1 3 50 780 775 973 19 4 50 635 zero 635 13 5 50 580zero 580 12 6 57 zero zero zero zero

Of the above results for the exemplified absorbent articles, absorbentarticle examples 1 and 6 do not meet the sensory or dryness indexes and.thus are not representative of the present invention. Examples 2-5 arerepresentative examples of the present invention.

In preferred embodiments of the present invention the absorbent articleshould preferably meet at least one of the requirement of vapourpermeability, air permeability, flexibility, caliper and rewet such thatthe article has:

a vapour permeability of greater than 100 g/m²/24 hrs, preferablygreater than 300 g/m²/24 hrs, more preferably greater than 500 g/m²/24hrs, most preferably greater than 700 g/m²/24 hrs, as defined in theabsorbent article vapour permeability test.

an air permeability of greater than 100, preferably greater than 250,more preferably greater than 500, most preferably greater than 6001l/m²/s, as defined in the absorbent article air permeability test,

a flexibility of less than 1.5N, preferably less than 1.0N, morepreferably less than 0.8N, most preferably less than 0.5N, as defined inthe flexibility test,

a caliper of less than 12 mm, preferably less than 9 mm, more preferablyless than 6 mm, most preferably from 5 mm to 1.5 mm,

a rewet of less than 500 mg., preferably less than 300 mg., morepreferably less than 200 mg., most preferably less than 100 mg asdefined in the absorbent article rewet test.

What is claimed is:
 1. A disposable absorbent article comprising thefollowing elements: a liquid pervious topsheet, an absorbent core, abreathable backsheet, and an odour control system, said absorbent corebeing positioned intermediate said topsheet and said backsheet, saidtopsheet, core and backsheet each comprising at least one layer, whereinsaid topsheet has a liquid retention of less than 0.22 g for a 2.0 gload in the topsheet liquid retention test, wherein said core has acaliper of less than 12 mm and has a vapour permeability of at least 200g/m²/24 hrs. as defined in the vapour permeability test and, whereinsaid breathable backsheet has a liquid permeability of less than 0.3 gat a 7 ml. load as defined in the liquid permeability test, wherein saidelements are joined such that said absorbent article has a dryness indexof greater than 0.5 and a sensory index of greater than
 50. 2. Adisposable absorbent article according to claim 1, wherein each saidelement has a wearer facing surface and a garment facing surface, eachof said garment facing surfaces forming a common interface with anadjacent wearer facing surface of an adjacent element, and wherein saidcore and said breathable backsheet are joined across less than 40% ofthe common interface of said garment facing surface of said core andsaid wearer facing surface of said breathable backsheet.
 3. A disposableabsorbent article according to claim 2, wherein said core and saidbreathable backsheet are joined across less than 20% of said commoninterface of said garment facing surface of said core and said wearerfacing surface of said breathable backsheet.
 4. A disposable absorbentarticle according to claim 2, wherein said breathable backsheet elementcomprises at least two layers, wherein each said layer has a wearerfacing surface and a garment facing surface, each of said garment facingsurfaces forming a common interface with an adjacent wearer facingsurface of an adjacent layer, and wherein adjacent layers are joinedacross less than 40% of said common interface of said adjacent layers.5. A disposable absorbent article according to claim 4, wherein saidadjacent layers are joined across less than 20% of said common interfaceof said adjacent layers.
 6. A disposable absorbent article according toclaim 2, wherein said wearer facing surface and said garment facingsurface forming said common interface are joined by spiral sprayedadhesive or fusion bonding.
 7. A disposable absorbent article accordingto claim 2, wherein said garment facing surface of said breathablebacksheet has an adhesive fastening means.
 8. A disposable absorbentarticle according to claim 7, wherein at least 60% of said garmentfacing surface of said backsheet is adhesive free.
 9. A disposableabsorbent article according to claim 7, wherein at least 80% of saidgarment facing surface of said backsheet is adhesive free.
 10. Adisposable absorbent article according to claim 1, wherein said topsheethas a liquid retention of less than 0.15 g for a 2.0 g load in thetopsheet retention test.
 11. A disposable absorbent article according toclaim 1, wherein said core has a caliper of less than 8 mm.
 12. Adisposable absorbent article according to claim 1, wherein said core hasa vapour permeability of greater than 600 g/m²/24 hrs. as defined in thevapour permeability test.
 13. A disposable absorbent article accordingto claim 1, wherein said breathable backsheet has a liquid permeabilityof less than 0.20 g for a 7 ml. load as defined in the liquidpermeability test.
 14. A disposable absorbent article according to claim1, wherein said absorbent article has a sensory index of greater than100.
 15. A disposable article according to claim 1, wherein saidabsorbent article has a dryness index of greater than
 2. 16. Adisposable absorbent article according to claim 1, wherein said articlehas a flexibility of less than 1.5N as defined in the flexibility test.17. An absorbent article according to claim 1, wherein said articlecomprises from 5 gm⁻² to 400 gm⁻² of said odour control system.
 18. Anabsorbent article according to claim 1, wherein said odour controlsystem comprises odour control agents selected from chelating agents,silica, zeolites, AGM, activated carbon and mixtures thereof.
 19. Anabsorbent article according to claim 1, wherein said odour controlsystem comprises AGM and zeolite.
 20. An absorbent article according toclaim 19, wherein said odour control system further comprises silica.21. A disposable absorbent article according to claim 1 wherein saidarticle is a sanitary napkin or a panty liner.